Containers are used to package many different kinds of items. One form of container used in the packaging industry is a carton. Cartons come in many different configurations and are made from a wide variety of materials. However, many cartons are foldable and are formed from a flattened state (commonly called a carton blank). Cartons may be made from an assortment of foldable materials, including cardboard, paperboard, corrugated fibreboard, plastic materials, composite materials, and the like and possibly even combinations thereof.
In many known systems, carton blanks may be serially retrieved from a carton magazine, opened up from a flattened state into an erected state, and placed in a slot on a carton conveyor. The erected carton may then be moved by the carton conveyor to a loading station where the carton may be filled with one or more items.
To permit the cartons to be readily opened up into an erected state from a flattened state, the blanks may be held in the magazine in a partially folded configuration and be partially glued along one side seam. Accordingly, each carton may only require opposite panels to be pulled apart to provide a tubular shape that is suitable for delivery to a carton conveyor. The carton can then be filled from the side while on the carton conveyor and any required additional panel folding and gluing can be carried out to enclose and fully seal the carton with one or more items contained therein.
However, such pre-folded and pre-glued blanks are not well adapted to shipping in bulk due to their asymmetric shape—being three layers thick on the glued seam area and only two layers thick elsewhere. Unstable stacking characteristic of such blanks requires the use of secondary containers and also reduces the number of blanks that can be shipped per unit volume. Both of these factors result in increased shipping costs which may be in the order of $8 to $10 per 1000 blanks compared to blanks that can be shipped in a completely flat arrangement. Additionally, some types of items do not lend themselves particularly well to being side-loaded into a carton; rather such products are more readily loaded into the top of an open-top carton. It can also be advantageous to be able to load some products through a relatively large opening, compared to smaller opening in a side-loaded carton.
Some other carton forming systems are adapted to forming a carton that can be top-loaded with a product. In such known systems, a carton magazine may hold a number of blanks that are completely unfolded and unglued and which lie completely flat in a stack in the magazine. However, currently quite complicated systems are required in order to fold and configure the blank so that it is suitable to receive one or more items. One known type of such system involves the use of a specially configured shoe device and associated plunger. A flattened blank can be retrieved from a magazine and then be placed above an opening in the shoe and the plunger can push the blank into a cavity formed in the shoe. The configuration of the shoe is such that various panels that make up the blank will be folded in relation to each other as the blank is pushed into the cavity by the plunger. The result is that a general carton shape is produced that may be further folded and glued to place the carton into a form suitable for delivery to a carton conveyor. Alternatively, the carton blank may be pre-formed with interlocking panels that once the blank is folded within the shoe device, side panels will interlock with each other to form a carton that maintains its form without the use of glue (e.g. “click-lock” carton blanks). Such cartons are formed with open tops. Once delivered to a carton conveyor the carton may be moved to a station where an item can be placed in the carton. Thereafter any required additional panel folding and gluing can be carried out to enclose and fully seal the carton.
However there are also significant drawbacks to these carton-forming systems. For example, a different shoe (and possibly plunger as well) may be required for each different sized/shaped carton blank. Additionally extraction of the formed carton from the shoe may require additional relatively complex machinery. This method of carton forming is also relatively slow and can only form cartons of limited depth.
In the formation of cartons from corrugated fibreboard material, it is also typically necessary as part of the forming process to fold over various parts of a blank made from a corrugated fibreboard material. However, current folding processes and machines are relatively complex.
Accordingly, an improved forming method and system is desirable which can readily form a container such as a carton from a generally flat blank. Furthermore, an improved forming method and system is desirable which can form cartons capable of being top loaded, with deeper trays than conventional “click-lock” formers and at higher rates of speed. Finally, an improved method and system is desirable which can be rapidly modified to accommodate cartons of different sizes and which produces cartons with increased structural stability and leak resistance due to the lack of a seam on the bottom portion of the carton.